In the environment of radio access technologies, extension of wireless network radio signal coverage by use of various types of relay nodes, e.g. base stations, has recently been a target of intensive studies. An amplify-and-forward relay node amplifies a received analog signal and transmits the amplified signal forward. This type of amplification improves the signal power but tends to amplify also the noise received with the actual content of the signal. A decode-and-forward relay node regenerates the received signal and transmits the regenerated signal forward. During the regeneration, the decode-and-forward relay node may apply various digital operations on the received signal. Due to transmission control measures during the regeneration stage, a decode-and-forward relay node typically provides better signal quality than an amplify-and-forward relay node. Use of decode-and-forward relay nodes to extend the coverage of a single base station in a radio access network is considered to improve the capacity of the single base station and to enhance the signal quality received by user equipment.
In a cellular telecommunication system, it is preferable to identify each base station, both “regular” base stations and relay nodes. Typically, a given base station is assigned with a global identifier identifying the base station in the whole public land mobile telecommunication network (PLMN) and a physical identifier identifying the base station in a geographically limited area. The number of physical identifier is typically limited to a few hundred in the PLMN and, therefore, the physical identifiers are reused. Conventionally, the identifiers of the base stations are assigned from a pool of available identifiers independently for each base station. While this is a very simple approach, better performance of the system may be obtained with smarter allocation of identifiers.